Surf pools often use conventional wave generators to produce waves. These conventional surf pool wave generators are most commonly pneumatic, vacuum; drop water system powered or are plows towed through the water to create a wave. The design of a surf pool is a very important factor in the production of waves. It is difficult to configure a wave pool to provide desirable waves, i.e., waves that are suitable for use in water sports such as surfing, body surfing, and kayaking. Even at the best natural beaches, perfect waves are rare. This is because the quality of the waves depends upon many factors, such as environmental conditions, such as tides, wind, and off shore storms.
Conventional surfing pools have typically been sized and configured so that when used for surfing, only a single surfer could safely ride a wave. Some wave pools have the capability to produce waves that break from the right hand side of the wave or the left hand side of the wave. Center breaking waves, which are more complicated and difficult to produce, are sometimes referred to as “Point” or “A-Frame” waves.
Surf pool construction and operation can also be costly. Surf parks can require a minimum of 10-12 acres, extensive infrastructure, staffing, and considerable energy consumption for the generation of waves. Surf Pools have been historical very costly to build. (10-25 million). With the high cost of concrete, rebar and labor cost, has led to a very slow expansion of surf parks across the world. The current Inventor has invented a new surf pool design and shape which has greatly reduced the size of footprint, cost and build out time, to build a surf pool. Surf pools that are capable of producing large, surfing waves can be even more expensive. The expense of generating surfing waves may be calculated on a cost per wave basis. Some facilities charge surfers based on their expected revenue per wave. In this current invention is a surfing pool design capable of increasing the number of surfers who may safely ride a generated wave, thereby improving the revenue per wave.
Surfing pools for generating waves suitable for surfing have been previously proposed and in some instances are used commercially in surfing pools or surfing parks. Previous surfing pools known to the present inventor have not been capable of generating waves suitable for surfing or tube riding over an artificial contiguous reef of varying surfable sections. Tube riding is riding a boogie board, surf board inside a breaking wave. The surfer typically rides the shoulder or the base of the wave at the leading edge of the break as it progresses laterally along the wave front, and the surfer can also ride inside the breaking part of the wave. In contrast to plunging or barreling waves are spilling waves, which break without forming tubes or barrels. For the purpose of our invention we will be focusing on plunging breaking waves that are formed by one contiguous artificial reef, with different reef sections as part of the contiguous reef.
Current reef inventions have been detachable, inflatable add ins to the pool. The current invention is one contiguous artificial reef structure that is intentional designed and shaped with different slopes, angles and contours and reef sections, to maximize wave height shape and form.
Waves that are generated artificially for surfing or recreation in a body of water known as a Surf-Pool must meet a number of criteria:
1. They must be of sufficient size and preferably exceed one meter in height. (3.28 feet).
2. They must travel at their natural velocity from the wave-making apparatus towards a sloping or contoured beach where they may break and dissipate their energy without being reflected.
3. For the installation to be economically viable, they must be produced at a high repetition rate, preferably in excess of 180 surfable rides per hour.
4. The waves should be essentially monochromatic, i.e. of a single frequency and without any significant smaller intermediate waves or harmonics or parasitic waves.
5. Waves should begin with a trough followed by a wave crest.
6. Waves should have ‘laminar flow’ characteristics as opposed to ‘turbulent flow’.
By controlling the bottom profile of the Surf-Pool, or the direction of the waves, or a combination of both, the waves should be caused to break or peel progressively from one end to the other, thereby creating waves that are of interest to surfers.
The peel angle is a critical term used to describe the speed that a surfer needs to travel to successfully traverse across the face of a wave. Good surfing waves break in a ‘peeling’ manner, where the breaking region of the wave translates laterally across the wave crest It is the area close to the breaking crest of the peeling wave, known as the ‘pocket’, which has the steepest face and therefore offers the most speed for surfing. The peel angle is defined as the angle between the trail of the broken white water and the crest of the unbroken part of the wave as it propagates shoreward. Peel angles range between 0° and 90°, with small peel angles resulting in fast surfing waves and large angles in slow surfing waves. There is a limit to how small the peel angle can get before it becomes impossible for a surfer to stay on the unbroken wave face, ahead of the breaking section; when this is no longer possible the wave is termed a ‘close-out’. On the other hand, as the peel angle increases towards the maximum of 90°, peel speed is reduced until it becomes too slow to be considered good for surfing. The extremes of peel angle are easy to envisage, but what peel angles are the best for surfing, and in particular, what peel angles should a wave break at for particular sized waves, different types of surfing and along specific sections of a break.
Peel angle has a huge effect on the rating of the skill level of surfers. Ratings are independent of surf break quality or the degree of difficulty of waves. As the peel angle is lowered away from 90 degrees the surfing level becomes more difficult. The ideal peel angle in the current invention is 45 degrees.
Peel angles are also influenced or enhanced according to swell direction, the angle at which a swell or unbroken wave approaches the reef angle. Storms at the incorrect angle may even “pass by” and not refract into the reef. Wave quality is enhanced when each reef angle is correctly matched with the ideal swell angle. Natural surfing locations in the ocean will harness swell energy generated by offshore storms when those storms are at the correct distance and angle. The correct swell angle enhances the swell size and direction as the swell approaches the reef angles at the ideal intersection.
It is the underlying bathymetry that influences the shape of breaking waves the most. The transition of breaker shape, from spilling through to surging, is mainly a result of increasing seabed gradient. On low gradient seabed's, waves break with a spilling form. As seabed gradients increase, breaker form tends towards plunging, and finally to collapsing or surging waves on very steep gradients. Of the four breaker types used to classify wave breaking intensity (spilling, plunging, collapsing and surging), spilling and especially plunging waves are required for surfing. Collapsing and surging breakers occur at the water's edge or where very steep seabed gradients come close to the water's surface. Such waves cannot be surfed because they lack a steep smooth face and/or they break at the water's edge, i.e. a surf zone through which breaking waves propagate does not exist. Indeed, surfing requires a steep unbroken wave face to create board speed for performing maneuvers.
While both spilling and plunging waves are utilized for surfing, the face of a spilling wave is relatively gently sloping and therefore provides low surf board speed in comparison to the steeper-faced plunging wave. The transition from long-boards prior to the 1970's to the short-boards used by most surfers today has meant that steeper and steeper waves are sought for surfing, since the lower volume short-boards require steeper more intense waves to ride. As a consequence, spilling waves are not preferred for surfing, except by beginners in the early stages of learning; it is plunging waves that are sought by today's surfers. The steep face of a plunging wave provides the speed needed to perform maneuvers, not unlike a steep mountain face required for skiing. In addition, the open vortex of the plunging wave provides the opportunity to perform surfing's ultimate maneuver, the tube ride, where the surfer rides under the breaking jet of the wave. Even though the seabed gradient has the greatest effect on wave breaking characteristics, wave height and period also affect the breaking intensity of waves.
There are many degrees of intensity at which plunging/surfing waves can break. As is implied by the sequence of breaker types (spilling though to surging), there is a transition between them and so it follows that within a category there is also a sequence, e.g. from gentle plunging to extreme plunging. This range of breaking intensity of surfing waves is reflected by the different terms used by surfers to describe surfing waves. As mentioned above, spilling waves are usually not preferred for surfing due to the difficulty in generating board speed on the gently sloping wave face. Surfers often term spilling waves as ‘fat’ or ‘gutless’, which indicates the lack of speed/power that can be generated on them while surfing. There are many descriptive terms that surfers use to describe plunging waves such as ‘tubing’, ‘hollow’, ‘pitching’ and ‘square’. However, exactly what is meant by a specific term, and how this relates to the wave's breaking intensity, is subjective and often depends on the experience of a surfer. A definitive description of wave breaking intensity is required to relate the subtleties of surfing waves in a way that can be universally understood. Thus, it is critical to have a highly-refined definition of the wave breaking intensity and to define the actual shape of the plunging wave profiles.
A large amount of work has been done on the profile shape of a breaking wave, mostly in wave flumes using linear seabed slopes. In order to describe wave breaking characteristics a non-dimensional parameter is employed, such as the Irribarren number, the surf scaling parameter or the surf similarity parameter. These methods take into account all forms of wave breaking (spilling through to collapsing). All are based on wave steepness (Hb/L∞) and a single value of beach slope, β. Where β is the beach slope. Once ξb is calculated, it is used to classify the breaker type, with higher values indicating higher intensity breaking and each breaker type classified within a range of values. For instance, 0.5<ξb<3.3 indicates plunging waves. However, while these methods give an indication of breaker intensity, studies of surfing wave shape have found that they do not well differentiate the transition between breaker categories. In addition, these values do not describe the actual shape of plunging/surfing wave profiles, or tube shape, which is imperative for describing surf quality when communicating reef design to the relevant parties
The ‘vortex ratio’ (i.e. tube length to width) is a measure of the ‘roundness’ of the tube and can therefore distinguish between subtle differences in the tube shape. As the ratio of vortex length to width approaches, the tube shape becomes more circular and less elongate and breaking is more intense. Breaking wave intensity is described in five categories from extreme to medium. Waves of greater than extreme are likely to collapse (although an exact limit to vortex ratio is yet to be established) and are therefore unsurfable, and waves of less than medium fall into the categories of gentle plunging and spilling, which, while still surfable, are generally not considered high-quality by surfers. The shape of each category is described in surfing terminology and examples of surfing breaks with similar breaking intensity and a picture of a wave breaking in profile at an example surfing break is also provided to give a full picture of the type of plunging wave that particular reef designs will produce.
The reef gradient responsible for the intensity of the breaking wave is the ‘orthogonal’ seabed gradient, that is the gradient the wave is travelling along, not the actual gradient of the reef (which is referred to as the ‘contour normal’ gradient). The orthogonal seabed gradient proved to be the most useful for predicting the breaking intensity because waves at surfing reefs do not approach normal to the seabed contours. On the contrary, waves must arrive at an angle to the seabed contours to provide a surfable peel angle, which is one of the most important factors required for high-quality surfing waves. This relationship between the reef gradient and breaking intensity is described by the linear equation, Y=0.065X+0.821, where X is the orthogonal seabed gradient and Y is the vortex ratio.
Even though the seabed gradient has the greatest effect on wave breaking characteristics, wave height and period also affect the breaking intensity of waves. Breaking intensity increases with increasing period and decreasing wave height. With respect to using equation above for predictions of plunging wave shape, it is important to know to what degree the changes in wave height and period effect the wave breaking intensity. This method of predicting the tube shape of breaking waves is simple and more than adequate for the purpose of predicting the tube-shape of surfing waves. However, it does not incorporate wave height or period and is restricted to the category of surfing, or plunging, waves. As discussed above, the plunging wave intensity is proportional to the beach steepness and inversely proportional to the square root of the wave height (Equation 1 above, the Irribarren number). This means that smaller waves will break with a stronger plunging nature than larger waves on a uniform slope. Scientifically, it has also been shown that waves break in water depths that are roughly proportional to the wave height (0.78 wave height to depth is the rule of thumb, but more generally ratios of about 0.5-1.0 wave height to water depth are observed). This means that smaller waves break in shallower water than larger waves.
With respect to wave breaking quality, as explained above, wave breaking intensity decreases with increasing wave height for a particular seabed gradient. This means that if a surfing reef gradient is linear, as the wave height increases the breaking intensity will decrease. Since high-quality surfing waves require steep wave faces to generate adequate board speeds needed for performing advanced surfing maneuvers, the lessening of breaking intensity with increasing wave height is a negative aspect of a linear reef gradient. However, since wave breaking intensity is related to the seabed gradient, a convex reef gradient compensates for the undesirable reduction in wave breaking intensity that occurs with linear gradients, i.e. as the depth increases so does the reef gradient which in turn ensures that breaking intensity does not significantly decrease. Thus, a convex reef face profile can be used to optimize surfing quality.
Reef Shape:
There are a variety of properties that put high-quality surfing breaks in a category of their own, but it is the seabed shape that has the largest influence on the form of a breaking wave and therefore the quality of a surfing break. The reef shape dictates the wave peel angles and the wave breaking intensity. However, while a peel angle of 45° is conducive to a surfing break for competent surfers in most cases a reef shape of 45° will result in peel angles considerably lower (i.e. faster) due to the process of refraction. Refraction changes the direction of wave propagation causing wave crests to align more parallel with the seabed contours. This is important for surfing because it alters the peel angle. The closer aligned the crest lines and the isobaths become, the greater velocity the surfer must attain to successfully ride the wave. Therefore, depending on the depth of the Reef, waves ‘wrap’ up onto the reef so that by the time waves begin to break the peel angle is significantly lower.
Analysis of surfing break bathymetries of reefs around the world, identified a series of commonly occurring components from which all surfing breaks are comprised. The geomorphic components were classified as ramp, platform, wedge, ledge, focus (point), ridge and pinnacle. These components account for the high wave quality at world-class ocean surfing reefs. Waves are refracted towards the favored orthogonal direction (intersecting or lying at right angles), as they travel up the ramp. Waves are refracted away from the favored orthogonal direction (intersecting or lying at right angles), as they travel up the wedge. Local Wave height convergence occurs as waves travel up a focus or (point). Very little refraction occurs as waves travel up a ledge. A steeper seabed gradient or slope and deflection is isobaths orientation results in a hollower and faster section in the wave as it travels up a ridge. An isolated region of shallow bathymetry causes the wave to rear up and steepen as it travels over a pinnacle.
In the Current Invention Our Surf Pool and Artificial Reef Design Criteria:                surfability over the widest possible range of wave heights, periods and directions in order to maximize the number of surfable waves per hour;        surfability across the full range of design wave heights;        suitability for excellent surfers and average surfers aspiring to be excellent;        at least one “section” hollow enough for tube riding;        a steep wall for board speed, and;        a fast and elongated take-off with sufficient steepness to allow adequate board speed for entry onto the main section of the ride.        